Couturier is a great player, and I would kill to have him on the flames. Certainly not at the expense of Tkachuk (who is younger, puts up slightly more points, and has as good or better possession and defensive metrics), but I would move many pieces if he were available. Someone above suggested Monahan... I would entertain that as a 1-1 but wouldn't add, and I can understand why philly fans don't think that is enough.
Not sure where the Carter Hart debate came in. That guy is also gold and it seems the flyers have finally found a suitable goal tender! Another thing that the flames can be jealous of.